Stability of nucleic acid bases in concentrated sulfuric acid: Implications for the habitability of Venus' clouds.

What constitutes a habitable planet is a frontier to be explored and requires pushing the boundaries of our terracentric viewpoint for what we deem to be a habitable environment. Despite Venus' 700 K surface temperature being too hot for any plausible solvent and most organic covalent chemistry, Venus' cloud-filled atmosphere layers at 48 to 60 km above the surface hold the main requirements for life: suitable temperatures for covalent bonds; an energy source (sunlight); and a liquid solvent. Yet, the Venus clouds are widely thought to be incapable of supporting life because the droplets are composed of concentrated liquid sulfuric acid-an aggressive solvent that is assumed to rapidly destroy most biochemicals of life on Earth.

Written content indicators of problematic approach behavior toward political officials.

Those charged with assessing and managing threatening communications must utilize risk factors that are behavioral, operational, and reasonably attainable during investigations. This project examined 326 written correspondence cases of an inappropriate, disruptive, or threatening nature that targeted political officials, with the specific goal of identifying written content indicators of problematic approach behavior. Results revealed that subjects who engaged in problematic approach activity toward their targets had more criminal history, past threat assessment activity, familiarity with firearms, past substance use, and indicators of serious mental illness.